5 km Deep and Back Again: United Downs Overcomes Pump Failure to Put UK’s First Geothermal Power Plant Within Weeks of First Electrons
United Downs: Britain’s First Deep Geothermal Power Plant Edges Closer to the Finish Line After High-Stakes Pump Swap at 5.2 km Cornwall, UK – November 2025 By: Robert Buluma Five kilometres beneath the rolling hills of Cornwall, in one of the deepest onshore wells ever drilled on British soil, a quiet but pivotal drama has just played out. After months of frustration, the failed downhole pump that threatened to derail the United Downs deep geothermal project – the UK’s first attempt to generate electricity from hot granite – has been pulled to surface. In its place, a new high-temperature Electrical Submersible Pump (ESP) supplied by SLB (formerly Schlumberger) is being readied for deployment 1,400 metres below the rig floor, inside a 5,275-metre production well that still holds the record as the deepest onshore borehole in the United Kingdom. The man at the centre of the operation, Ryan Law, Founder and CEO of Geothermal Engineering Ltd (GEL ), has been unusually candid on Linke...